I believe its ok to sell before a certain date of manufacture ,if they are antique pieces then its totally ok
You'll have to have them verified and dated by an expert.
Big auction houses with be happy to date and value your pieces if you lead them to believe you would be selling them through their auction house
Once you know that the date is before the legislation and theyre legal to sell then take them anywhere
RESEARCH RESEARCH RESEARCH
Are you sure they're ivory ? things like scrimshaw ,nic-nacs made from whale and walrus, teeth and tusks are totally legal to sell and are very sought after,some of the better quality scrimshaw goes for thousand.
Scrimshaw will almost have some dedication to the sea or ships upon it.
Ivory usually is sculpted into small figures or animals ,sometimes with an incredible degree of skill and attention to detail that is almost celestial,sometimes its a crude lump like figure of Budda
Got some pics
1976 Raleigh Chipper,1991 Muddy Fox Adventurer,1991 Claud Butler Ventoux 400 ,1992 Raleigh Diablo ,1992 Rudy Project, 1995 Cannondale M200 ,1997 Santa Cruz Tazmon ,1997 Specialized Stumpjumper ,1997 Specialized Rockhopper ,1997 Marin Quake 9.0,1998 Marin Pallisade trail ,1998 Raleigh Torus,1999 Orange Clockwork , 2005 Kona Hahanna ,2007 On-One Inbred ,2010 Orange Pure7 And of course The Ti
The Marvellous Mechanical Hope Collection ,and other Hope niceties